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Homework Help: Hydrogen radial wavefunction

  1. Jan 15, 2009 #1
    I am solving the Hydrogen wavefunction using FORTRAN.
    Now using the Euler method, I am given a solution to match which is given by u10(r) = 1.06r*exp(-3.74r) (where unl(r) = rRnl(r) in general) which says it has a normalisation chosen to match what i should get from my code.

    Then I use the backwards Euler method getting a more accurate solution with a correct shape and a much larger amplitude. I then normalise this and plot it against the analytic solution given by
    u = 1/pi^1/2*(1/ao)^3/2*r*exp(-r/a0) which is apparently also normalised.

    I am working in natural units so h-bar = c = 1 and me = 511.7keV the electron mass, which implies that my Bohr radius = 0.26737keV^-1 and I am working in units of r given by keV^-1 also.

    so this would imply that the units of u for the analytic solution must be keV^(1/2) however looking at the original equation shouldn't the units be keV^-1 as u = rR(r) where r has units keV^-1 and R(r) is dimensionless, I'm confused. Is my normalisation unit calculated in fortran supposed to have units like the analytic normalisation constant?

    On my graphs should I just put no units? :S
    Any suggestions would be appreciated, units of wavefunctions has always confused me.
     
  2. jcsd
  3. Jan 16, 2009 #2

    Redbelly98

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    Wavefunction units can be tricky, but you can get it from the normalization condition:
    ∫ Ψ*Ψ dx dy dz = 1​
    Since the "1" is dimensionless, and "dx dy dz" is a volume, the wavefunction must have units of volume-1/2 or length-3/2
     
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